Zig-Zag板条泵浦的2.12μm激光器

 为了实现窄脉宽、高峰值功率2.12 μm激光的稳定输出,设计了基于侧面泵浦Zig-Zag 板条产生1.06 μm基频光,进而泵浦KTP晶体通过II类相位匹配产生2.12 μm激光的光参量振荡实验。对外腔及内腔进行了实验研究,分别获得了1.53%和2.86%的电光转换效率。在20 Hz频率下内腔2.12 μm输出能量达到70 mJ以上,脉宽7 ns~9 ns。其中内腔实验中能量输出稳定度接近8%。     

光纤激光泵浦周期极化晶体双波段激光器

针对激光定向干扰系统要求对抗1 m ~3 m和3 m ~5 m 2种类型探测器,需要输出相应2种波段激光,通过高重频调Q技术和种子注入光放大技术,获得高功率高光束质量1.06 m光纤激光输出,外置起偏器获得2束激光输出,分别为泵浦周期极化钽酸锂和周期极化铌酸锂晶体,实现高功率1 m ~3 m 和3 m ~5 m激光输出。在电源输入电流60 A,调Q驱动频率50 kHz的条件下,获得最高功率7.5 W的2 m激光和4.2 W的3.9 m激光,频率转换效率为39.5%。实验结果表明:通过光纤激光器泵浦光参量振荡器,可获得高功率1 m ~3 m和3 m ~5 m双波段激光输出。     

Raman and mid-infrared spectroscopic study of geometrically frustrated hydroxyl cobalt halides at room temperature

Mid-infrared absorption and Raman spectra of the geometrically frustrated material series,hydroxyl cobalt halides β-Co 2 (OH) 3 Cl and β-Co 2 (OH) 3 Br,are first,to the best of our knowledge,measured at room temperature,to study the corresponding relationship between their vibrational spectral properties and crystal microstructures.Through the comparative analysis of the four spectra we have categorically assigned the OH-related vibration modes of hydroxyl groups in the trimeric hydrogen bond environment (Co 3 ≡OH) 3… Cl/Br,and tentatively suggested vibration modes of O-Co-O,Co-O and Cl/Br-Co-Cl/Br units.These results can also become the basis for analysing their low-temperature spectral properties,which can help to understand the underlying physics of their exotic geometric frustration phenomena around phase transition temperatures.     

磁几何阻挫材料羟基氯化钴的中红外光谱特征

使用3种光谱仪测量了磁几何阻挫材料羟基氯化钴Co₂(OH)₃Cl的中红外(4000—400 cm^-1)吸收光谱,筛选出确信为Co₂(OH)₃Cl的本征吸收峰数据,结合已知的晶体结构参数,指认了官能团和指纹区相应谱峰的来源.在指认中着重探讨了羟基伸缩振动基频模vOH的具体实验数据,根据固体中氢键的特点,以Co₃—O平均距离为基准,推算了本样品 关键词： 红外光谱 几何阻挫 羟基氯化钴 三聚氢键     

倒Y型四能级量子系统中亚光速和超光速传播现象的转换研究

研究了探测场、耦合场和驱动场三场作用下倒Y型四能级量子系统的光学特性,利用数值模拟的方法探讨了外加相干驱动场的拉比频率和失谐量变化时系统对探测光场吸收特性的影响. 通过绘制三维立体图,发现了探测光场的群速度在电磁诱导透明窗口处的变化规律,并且选择合适的驱动场拉比频率和失谐量,可以在理论上实现亚光速和真空光速以及超光速传播之间的转换. 关键词： 倒Y型四能级 群速度 超光速传播 亚光速传播     

Microstructured hydroxyl environments and Raman spectroscopy in selected basic transition-metal halides

Raman vibrational spectra of the selected basic (hydroxyl OH and deuteroxyl OD) transition-metal halides, geometrically frustrated material series α-, β-, γ-Cu₂(OH)₃Cl, α-Cu₂(OH)₃Br, β-Ni₂(OH)₃Cl, β-Co₂(OH)₃Cl, β-Co₂(OH)₃Br, γ-Cu₂(OD)₃Cl, and β-Co₂(OD)₃Cl are measured at room temperature and analysed to investigate the relationship between the microstructured OH environments and their respective Raman spectra. Among these selected samples, the last two are used to determine the OH stretching vibration region (3600 cm^-1—3300 cm^-1) and OH bending vibration region (1000 cm^-1—600 cm^-1) of OH systems in the spectra. Through the comparative analysis of the distances d(metal—O), d(O—halogen), and d(OH), the strong metal—O interaction and trimeric hydrogen bond (C_3v, C_s or C₁ symmetry) are found in every material, but both determine simultaneously an ultimate d(OH), and therefore an OH stretching vibration frequency. According to the approximately linear relationship between the OH stretching vibration frequency and d(OH), some unavailable d(OH) are guessed and some doubtful d(OH) are suggested to be corrected. In addition, it is demonstrated in brief that the OH bending vibration frequency is also of importance to check the more detailed crystal microstructure relating to the OH group.     

Multiformity of Optical Quantum Coherence Systems with Y and Inverted Y-type Schemes

Y and inverted Y-type four-level schemes for optical quantum coherence systems, which may be intuitively considered to be very simple, have not been studied intensively till now. In this paper, we present the multiformity of these two types of schemes by considering that they can be classified into nine possible level styles as the second-order sub-schemes using laser fields. Further we point out the complexity of their more than one hundred realistic configurations as the third-order four-level sub-schemes that may appear in the optical quantum coherence experiments. Throughout this paper we review which configurations have been studied in some research aspects and which ones not, according to our knowledge, in order to be propitious to next steps of theoretical and experimental investigations, especially for applications in the fields of quantum optics, quantum information science, laser spectroscopy, and so on.